Researcher interests: The physical chemistry of humic substances, minerals and their interactions. Effects of organic matter on soil fertility and structure. The role of organic matter and bacteria in the iron nutrition of plants. Composting of agricultural wastes and the application of composts as soil conditioners and as peat substitutes in horticulture. Chemical transformations in composts. Suppressiveness of composts to soil borne diseases. Effects of dissolved organic matter in wastewaters on soil structure, surface tension and contact angle of soil pore water, and the hydraulic conductivity of soils.